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arXiv · 1407.4967

QCD sum rules for the nucleon and the non-locality of quark condensates

M. G. Ryskin·V. A. Sadovnikova
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Abstract

We emphasize the role of the x dependence of the quark condensate <|\bar q(0)q(x)|> originated by the zero fermion modes in the instanton vacuum. The effect is not negligible since the inverse size of the instanton 1/\rho~600MeV is comparable with the value of Borel mass M~1GeV. Using as an example the sum rules for the nucleon we show that this "non-locality" may strongly affected the conventional results obtained under the <|\bar q(0)q(x)|>=<|\bar q(0)q(0)|> approximation.

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M. G. Ryskin, V. A. Sadovnikova. 2014-07-18. QCD sum rules for the nucleon and the non-locality of quark condensates. https://arxiv.org/abs/1407.4967

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